Special Visitors

Many years ago, I planted a line of three dogwoods (not our native species; rather, Cornus sanguinea) just outside our front porch. This is the part of the garden I call our ‘woodland’ garden, because it gets dappled shade all day from our mature trees. I have a lot of natives here (various Ribes, spice bush, coffee berries, etc, as well as some true geraniums, things that can handle dry shade). I wanted the dogwoods because of their bright red stems, but I haven’t been pruning them correctly I guess, because they have yet to show the flame color their name suggests.

Anyway, I can see them from our living room. Tom and I were sitting on the couch chatting yesterday and I was looking out at them and admiring the sun shining through their leaves when I realized - hang on a second, what am I seeing? - those leaves aren’t supposed to look lacy. But they do now, and for a very good reason - one that makes me super happy. They are being used to build the nests of leaf-cutter bees.

image credit: Planet Bee Foundation

Leafcutting bees (Megachilidae family) are solitary native North American bees who use soft leaves and flower petals to create nests for their young. The female bee finds a long channel or tube, for instance in wood or in a hollow stem, and painstakingly creates chambers for her larvae, depositing some bee bread (a little mound of pollen) and an egg in each one. Each chamber is separated by a wall made up of chewed leaves and mixed with resin or mud. The bees spend the winter as mature larvae in the chambers; in spring, they pupate, then chew their way out of the nest and go off to mate. The adults are active only in spring and early summer; most of their lives are spent in the cells as larvae.

We have at least 75 species of leafcutter bee in California. They are generally smaller than honeybees, tend to be more of a grayish color, and carry pollen on their bellies rather than on their legs like honeybees. They are wonderful pollinators, and in fact there is an introduced species that is a major pollinator of alfalfa and is economically important. The family Megachilidae also includes Mason bees and Wool Carder bees.

The ‘damage’ to the margins of the leaves is quite slight and doesn’t hurt the plant at all. The bees are extremely gentle and in fact, in all my years of taking pictures of bees in my garden, I’m not sure I’ve ever gotten a photo of one. I’m delighted to find this evidence of their existence in my little ecosystem and I hope I get the privilege of finally meeting one.

Wasps: One Sign of a Healthy Ecosystem

When I started teaching at Merritt College, I was “given” the Environmental Center property as a place to hold my labs - basically, as a place to grow a garden. In years past, it had been used for that purpose (though, I would argue, not to its full potential), and even held a few remnants of the old raised beds. But it had long been abandoned and unused; my co-workers had several truckloads of junk and trash hauled away, which revealed a rather shabby and sad space. The ground was either rocky, or covered in weeds. The outbuildings were mostly being taken over by nature, with mushrooms growing out of roof tiles and critters nesting in walls. Invasive Himalayan blackberry vines covered every corner. The first lab I held there, I had the students spend an hour just being in the space, mapping it out, taking an inventory of what was there, noting how the sun might move across the sky, how the wind moved through the space, and what they thought could be done with the property to make it a ‘real’ farm. On that day, I watched them move through what would eventually become our garden, and took my own inventory of the space. And I realized something that day. I realized that there were no bugs.

A female (identified by the curled antennae) tarantula hawk-wasp taking a break in the Environmental Center garden, on my newly formed paths

Actually, no birds either, except one curious scrub jay. No scuttling lizards. Nothing zooming past, not even a pesky fly. Now, sure, it was late January, but that’s no deterrent in coastal California. If it’s above 50 degrees (and it was, that day, as it is nearly every day of the year in Oakland), bugs are generally out getting some stuff done. But not at the Environmental Center.

My feeling was that the space had been abandoned so long, and was so full of invasive (rather than native) plants, and was so crowded with non-flowering weeds (mostly exotic grasses), that nothing really wanted to live there. This is not an uncommon thing. Urban spaces are increasing across the globe, destroying valuable habitat for all kinds of creatures. How can an insect live in a place with only concrete, glass, and steel? Urban spaces not only lack flowering plants, they also often devoid of any kind of slow-moving water, crucial for drinking but also for many insect nurseries. Cities trap heat to become even hotter than their surroundings, becoming ‘urban heat islands,’ uninhabitable to many species. Vehicles rush around, creating dangerous circumstances for any surviving insect just trying to get from here to there. And people are fearful of insects, generally, and are quick to squash and kill anything they don’t understand.

As I’m sure you’ve heard, insects are absolutely vital to our human lives. Not only do they provide pollination services, they are a critical food source for so many animals that live further up the food chain. Many, like wasps, are also important biological controls, keeping a check on other insects, feeding them to their young. And others, including yellow jackets, are valuable detritivores, cleaning up dead animals and other organic matter so that we are not buried in refuse.

A common blue mud-dauber wasp dragging a spider to its nest to feed its larvae, at the Environmental Center

I know that over the (almost) ten years I’ve been writing this blog, I’ve given some mixed messages regarding pests. I have used yellow jacket traps in the past. I mean, yellow jackets are annoying as hell, there’s no question about that. Eating outdoors is one of the absolute joys of summer, and some yellow jackets make that next to impossible. They also bug my chickens and my honeybees, which I don’t like. So for many years, I rationalized my trapping, until I started to read more about general insect decline and the way that decline affects us. (By the way, if this is something you’re interested in learning more about, I’d recommend checking out Dr. Dave Goulson, or Dr. Doug Tallamy.) Now, I make it a practice not to kill any insect on purpose, and rather to learn as much about them as I can. I find that when I learn more about something, I become fascinated with it, and that in turn leads me to appreciate it fully.

This point was driven home to me when my folks shared that they’d recently read an article in the Wall Street Journal about how beneficial yellow jackets really are. I had been talking about insects in a positive light for years, but it wasn’t until my parents read an article for themselves that they had greater fascination for the subject. This made me realize that, though I’ve written on this subject before (here, and here and here, among others) it really bears writing about again.

There are several different kinds of yellow jacket wasps in California. They are generally either in the Vespula or Dolicovespula genera. Some nest in the ground, in old rodent burrows, and some nest in walls or trees; some that are strictly insect-and-nectar eaters, and some which are scavengers. The scavengers are the ones that annoy us at picnics. They are also the ones who generally will enter a trap. However, the others are great for ecosystem health, and deserve our respect and admiration.

A yellow jacket pollinating at Poppy Corners

And there are many other interesting wasps, such as the ones in the photos near the top of this post. Many wasps, such as the tarantula hawk-wasp and the common blue mud dauber wasp, take other bugs home to their nests to feed their young. The tarantula hawk-wasp, for instance, stings a tarantula between the legs (!) and drags it back to the nest, where it then lays one egg on the spider, takes pains to keep the spider alive until the egg hatches into a larva, which then feeds on the living spider until it pupates. I mean, the stuff of nightmares, yes? And yet also intriguing. Other predatory wasps do this with the very caterpillars that threaten to eat our crops.

In fact, in a 2021 study by the University of London, it was shown that “predation by insects -- as biocontrol to protect crops -- is worth at least $416 billion (US) per year worldwide,” and that wasps actually regulate populations of agricultural insects. This is a priceless service.

Another priceless service that wasps perform is pollination. Many wasps use nectar for their primary source of daily energy (the ‘meat’ is for larval development only), and the study states, “pollination by insects is vital for agriculture, and its economic importance has been valued at greater than $250 billion (US) per year worldwide.” These are not small numbers. Our food supply is already under threat, for oh so many reasons - so let’s use any and all of the free ecosystem services that nature provides us, shall we?

an old paper wasp nest in the eaves of our train shed at Poppy Corners

With all of these services firmly in mind, at the Environmental Center, one of the first jobs I gave the students was to plant a pollinator garden. I had obtained a grant for seed from Pollinator Partnership, and they sent us a large bag of various native California wildflower seeds. We knew that our vegetable and fruit plantings would attract pollinators, but we wanted to ensure as much diversity as possible, and that seed grant gave us another 30 species of flowers with which to attract and feed insects. (Also deer, but that’s a story for another time.) And once the goldfields started coming up, and the tidy tips, then the gilia and the poppies, the bugs started arriving - hover flies came first, then honeybees, then butterflies, and finally now, on these hot summer days, I’m finally seeing the wasps. I’m delighted. Now that there is the buzzing and zooming in the air, I’m starting to see lizards, and skinks, and snakes. Birds of all kinds have found us. Each of these species brings a new set of challenges, but that’s ok - we know that having a healthy ecosystem brings far more benefits than it does problems.

As the garden evolves, my plans for it does, too. I intend, this fall, to have one class build an herb spiral and plant fruit bushes and trees, which will attract even more pollinators. Another class is going to create a garden full of traditional, cultural crops, which should bring in even more native insects. I look forward to seeing the ecosystem develop and create a closed loop, where everything within the loop thrives, including the humans who eat the food grown there.

The Cedar Waxwing Invasion

Oh my goodness, what a day. Upon finishing my homework, I went back to my room to grab my iPad. A flurry of activity out the south-facing window where the Catalpa tree is located caught my attention. Birds. Tons of birds. Larger birds. All of them in the Catalpa, flying in and around and resting on the branches. I spotted half a dozen Robins and smiled, because they haven’t been around lately. But there were other birds I didn’t recognize. Then one of them rested on a branch nearer to the window, and I could see a stripe of yellow at the base of its tail. Could they be Cedar Waxwings? I’ve never see them in our yard before and couldn’t believe it. I grabbed my camera and headed outside.

The activity and noise were just tremendous. Big groups of waxwings and robins flying all around the tree and also perching. I couldn’t get any good pictures but you can just see the crested head of a waxwing in the photo above. It was hard to make sense of all the activity - what was going on? Robins eat invertebrates, and it just started raining again, so that would explain why they were perched and ready for action. But the waxwings - I couldn’t understand what was happening. I looked down for a moment and that’s when I saw huge splotches of black bird poo everywhere, dotting the ground and the plants.

Things started to get clearer. Waxwings eat berries, but there aren’t any berries in my yard right now except for some yellow Toyon berries and they weren’t in the toyon. A pattern started to emerge - the waxwings would rest in my tree, then fly across the street to a huge group of trees across the street. Upon closer inspection, I realized those trees were Privet. The waxwings came to eat the huge supply of privet berries. And now they were pooping them out all over my yard.

Here’s what I read in Audubon:

“With thin, lisping cries, flocks of Cedar Waxwings descend on berry-laden trees and hedges, to flutter among the branches as they feast. These birds are sociable at all seasons, and it is rare to see just one waxwing. Occasionally a line of waxwings perched on a branch will pass a berry back and forth, from bill to bill, until one of them swallows it. “

Get this - a group of Cedar Waxwings is called a ‘museum’ or ‘ear-full’ of waxwings. They are loud.

More of what I read:

“Except when nesting, almost always forages in flocks. May hover briefly while plucking berries or taking insects from foliage. Often flies out to catch insects in mid-air.”

They could all be catching newly emerged mosquitoes, which would be wonderful - we have warmed up about 10 degrees at night and mosquitoes could definitely be hatching from standing puddles of water from last week’s deluge. I looked up robins, and it appears that they don’t just eat insects - they also glean fruit. So it looks like all of the birds are enjoying those horrible privet trees. Guess they’re good for something.

Waxwings are apparently common here in winter, but migrate north to breed, all the way to Canada. Hopefully they’ll hang around for a while so I can admire them!

Passionflower Vine/October Wreath

Oh my goodness, I could not be happier about the South Pollinator Garden right now. I know I’ve written about this garden, and the pollinators, and specifically the Gulf Frittilaries before. But I have to write about it again, because I’m having such a good time visiting the Passion Vine! And I’m not the only one…. day after day I go out there to see what’s happening, and since it’s right next to the sidewalk, there is always someone else there checking it out too. It’s so fun to stand there and watch and chat with someone else about the ecosystem in the Passion Vine! They’ll see something I didn’t see, and I’ll see something they didn’t see, and it’s like this big treasure hunt. Sometimes I wish I still had little kids, because wouldn’t this be a great opportunity for them to learn about a particular life cycle?

From our side

Ok, so back in late spring, my neighbor rebuilt this fence and cut down all the bushes on his side that were growing tall and keeping the deer out of our garden. I knew I needed to put something here that would add that height, so the deer wouldn’t take advantage of the gap in security. I bought a rather cheapo folding trellis from Gardener’s Supply (I can’t afford anything fancy, and building something would take too long), stuck it along the fence line, went to Annie’s Annuals and bought eight passionflower vines, which I then planted at the base of the trellis, and made sure the drip line was all along that base line. I think 4-5 of the plants survived and started climbing. They weren’t even a foot high before I noticed Gulf Frittilary butterflies had found them, which made me very happy.

From the neighbor’s side

Through the summer, the vine grew up and along the top of the trellis, fulfilling perfectly the job of deer deterrent. The pollinator garden grew up around it, the zinnias and the tithonia reaching for the sky, some higher than our redbud tree. And the butterflies just kept coming, flitting about in a mating dance, sipping nectar from the flowers, and laying eggs on the passionflower leaves.

The vine has deeply divided simple leaves, which are lovely to look at, along with the tendrils that cling to the trellis. And of course the flowers are beautiful. The butterflies lay a single egg at a time (or at least I’ve never seen them in clusters) and the eggs are gorgeous and shimmery when you get a lens that lets you actually see them clearly. The egg is there 3-5 days before it hatches. They are usually found on the topside of a leaf. They start out yellow, and then turn brownish before they hatch.

The female butterfly tests the chemical compounds in the leaf with her antennae, and knows that the plant is the correct host for her babies. The caterpillars eat the leaves, ingesting those chemical compounds, which hopefully makes them less attractive to birds. The larvae has five instars, or stages of growth, before they finally pupate on the passion vine (I can’t wait to see chrysalises!!!! Chrysali? oh who knows). The caterpillars are kinda cute in their own right, brownish reddish, and get this sort of blue-ish stripe as they get bigger.

The passionflower vine is now starting to fruit (see top picture), which is an added bonus that I didn’t really expect. I mean I know they fruit but I wasn’t sure if this was a fruiting variety. What a welcome time of year for fruit! I think they are supposed to get sort of hard and purplish brown, and then they are ripe. More on that as it happens. Passionflower jelly, here we come!

I’m not sure I’ve ever seen such a complete life cycle of any insect before, other than my honeybees. I plant specific flowers for insects all the time, such as fennel for anise swallowtails (had the caterpillars and adults, but never seen eggs or chrysalises), and dutchman’s pipevine for pipevine swallowtails (never seen any activity on it or around it, but hatched a chrysalis I brought in from a nearby creek), but this is the first time I’ve seen the whole thing from start to finish. It’s thrilling to watch.

And oh yeah, here’s the October wreath, finally:

This one is made out of California Bay Laurel. My mom gave me the idea. She grows several of these trees in her yard, and about once a year I ask her for some branches to dry as I use the leaves for cooking. She brought me a whole sheaf and said they could be used as a wreath AND a food. It was such a great idea that I promptly followed through. This plant smells nice fresh or dry, and will turn a handsome dusty sage color as it starts to lose moisture, so it should look good until November.

The Ecology of Leaf Litter

There's a lot of ecological buzzwords that can be confusing, or we assume we know what they mean even if the real meaning is lost on us. One of those buzzwords is biodiversity, which simply means 'the variety of life in the world or in a particular habitat or ecosystem.' This concept is important, if we want our gardens to be healthy ecosystems. Well, what is a healthy ecosystem? One where the biological community of interacting organisms is robust, eating and reproducing and going about their tiny lives. And why is a healthy ecosystem important? Every species, no matter how small, has an important role to play in our environment. Depending on how you see things, our planet either evolved, or was designed to evolve, in perfect harmony. Our human life is part of that and has an important role to play. But things have gotten a bit out of balance, and our human environments have encroached on the wild ones, and we no longer live in harmony with that biological life. The loss of habitat for these creatures is staggering. If we lose this perfectly evolved system that nature has developed, we lose everything. Recently the UK paper The Guardian published an article about the decline of insect populations - it's worth a read (you can find it HERE). There is scientific evidence that all insects are disappearing - not just the highly publicized ones like bees and butterflies - but all insects. We rely on a healthy, diverse ecosystem, because we are part of it, and if it disappears, we are in serious trouble.

We may not be able to affect change on a large level, but one thing we can control is how we interact with the space directly around us, namely, our yards. We all want beautiful spaces surrounding us, and beauty is important. But do we want beautiful dead spaces? Or beautiful living spaces? I would argue that the living space is actually more beautiful because of its diversity of creatures and plants. 

One way to increase insect life in your garden is to allow leaves to accumulate, rather than raking them and disposing of them each year. Now I know there are places in your yard where you must rake. I get it - I have to clean leaves up off our driveway and sidewalks every year, so I know. Plus sometimes the leaves can make such a deep mulch that they kill certain plants. So we can agree that there are portions of the yard that need tidying. But we also all have certain parts that are tucked away, and other parts that could do with a layer of mulch. Why not leave the bulk of your leaves on the ground to decompose naturally?

It turns out that leaf litter is an important ecological habitat, harboring larvae and eggs as well as overwintering creatures. Worms, spiders, and caterpillars spend a lot of time in leaf litter, and both fungi and bacteria feed on it and convert it to nutrients for your nearby plants. The leaves are also nature's way of getting nutrients back into the soil, as they provide nitrogen when they decompose under the tree. 

The Nature Conservancy is running a campaign right now to raise awareness about the importance of letting leaves lie, and you can take the pledge to be a 'lazy gardener' at their site, HERE. There's also some great information about what leaves do for the ecosystem of your garden, and why to make brush piles around your yard, leave dead tree snags standing, and eschew chemicals. Honestly, that last point might be the most important of all: Do not use chemical fertilizers, herbicides, or pesticides on your property. 

I took the pledge this year, but honestly I've been actively working on increasing our insect population for quite some time now. We use wood chips in a large portion of our yard, which helps to harbor all these creatures, as well as provide organic matter to the soil, conserve moisture, and deter weeds. We let a lot of our leaves and plant clippings mulch naturally beneath the plants. I leave seed heads at the end of the season for the birds. I've spent years making wood piles, brush piles, and stone piles, all to attract lizards and snakes (lizards, we've got by the thousands; snakes, none that I have seen so far). As you know we try to have flowers blooming as much of the year as possible to support insect life. I haven't used any pesticides, organic or chemical, in many years (though I do use organic products in my beehive to inhibit the varroa mite load, and I occasionally use copper on my peach tree), and we have no need for herbicides, as I hand pull any weeds that come up (and they are rare). I've stopped using chemical fertilizers completely, as the high salts that result can kill soil life. (More to come on a later post about all I have been learning about soil life.)

The result of this is that our garden is always teeming with insects, of all kinds. Both 'good' and 'bad.' Predator and prey. It's a healthy, living system that brings me a great deal of joy. The other day I was doing homework at the dining room table when I saw the chickens run to the edge of their run and squawk. I went outside to see what was happening, and a neighbor had stopped by to look at the garden. She was leaning on the fence smiling. "I'm just watching all the life, " she said, as butterflies and bees flitted in the flowers in front of her. Can I just say how pleased I was? How full of satisfaction? And it's EASY, not hard. Just pledge to be a little bit of a lazy gardener. 

Edit 10/23: Just saw this article in the Guardian from Friday regarding the same issue, another good read, related to the one above.